Chlorocyclization of Alkenoic Thioester.

This study introduces a novel method for ring-closing chlorosulfenylation of alkenoic thioesters using N-chlorosuccinimide in hexafluoroisopropanol under mild conditions. This reaction efficiently forms five-membered cyclic sulfur compounds with high selectivity, representing a significant advancement in the synthesis of chlorinated S-heterocycles. Computational analysis using density functional theory demonstrates the superiority of thioester nucleophiles over traditional benzyl sulfides in this reaction, highlighting the energetic preference for thioesters.

Ring-Closing Disulfenylation of Alkenoic Thioester.

This study demonstrated for the first time that alkenoic thioesters can be effectively used as nucleophiles in ring-closing disulfenylation reactions. Our investigation revealed that the reaction in hexafluoroisopropanol with an electrophilic sulfur reagent significantly enhances the product yield. We gathered experimental and theoretical evidence to support the superiority of thioesters over the traditionally used benzyl sulfide.

Halocyclization of Alkynoic Thioester and Oxidative Aromatization in One-Pot.

This paper reports the halocyclization of alkynoic thioesters, as -nucleophiles, with -halosuccinimide, followed by oxidative aromatization with the same reagent for the one-pot synthesis of thiophenes, important heterocycles exhibiting remarkable applications in different disciplines. Brief mechanistic studies were also performed to elucidate the halocyclization process. The potential diverse applications of the product, dihydrothiophene, were also assessed.

Mechanistic Studies on Bromocyclization of Unsaturated Thioester by Density Functional Theory and Experiment.

Using sulfur-containing nucleophiles in halocyclization has been underexplored notwithstanding their potential to generate novel -heterocycles and despite the extensive exploration of oxygen, nitrogen, and carbon nucleophiles. In this study, we focused on the bromocyclization of alkenoic thioesters with -bromoacetamide, which leads to the formation of cyclic bromosulfides. Investigation into the mechanistic pathways of these reactions revealed that the sulfur atom behaves as a nucleophile, leading to -acetylsulfonium intermediates.